Food detective: Inulin

It’s popping up in all sorts of products. This added fibre has good and bad effects.

What exactly is inulin?

Not to be confused with insulin, inulin is a starchy carbohydrate that’s present in garlic, bananas and asparagus. As an ingredient in processed foods, however, inulin is a chicory-root extract.

What does inulin do?

Inulin boosts the soluble fibre of foods, drinks and powdered supplements. Manufacturers love inulin because it makes their diet products taste slightly sweet and delivers fat-like creaminess (but it’s actually free of extra fat and kilojoules). What’s more, it does this invisibly — inulin has a subtle flavour and dissolves without forming a sludgy layer at the bottom of the drink in the way some other forms of fibre do.

The body can’t digest inulin, so it stays in the gut. Here, it acts as a prebiotic, providing food for our friendly gut bacteria. After feeding on inulin, these bacteria flourish and multiply to create a healthy intestinal ecosystem. These ‘good’ bacteria also break down inulin, turning it into gases that we sometimes pass as wind. This transformation not only adds bulk to stools and helps lower blood cholesterol, but also cuts the number of kilojoules that the body extracts from foods.

How can I spot inulin in packaged foods?

When you’re reading ingredients lists, look for the words dietary fibre, chicory-root fibre, fructans or oligofructose (FOS) — all of which are other terms for inulin.

Is there anything else I should know?

Inulin can trigger excess wind, belly bloat and abdominal pain in some people. If you suffer from irritable bowel syndrome or are following a low-FODMAP diet, you should try to avoid inulin.

The bottom line

Inulin adds sweetness to many packaged foods and drinks. As a form of fibre, inulin helps us feel full, yet it’s virtually kilojoule free. Still, if you suffer from belly bloat or discomfort, be wary of inulin.